/Engine/Source/Runtime/Core/Public/Misc/CoreDelegates.h
Callback when the application has been activated by protocol (with optional user id, depending on the platform)
static [TMulticastDelegate](API\Runtime\Core\Delegates\TMulticastDelegate)< void(const [FString](API\Runtime\Core\Containers\FString) &[Parameter](API\Plugins\Niagara\ENiagaraInputNodeUsage), [FPlatformUserId](API\Runtime\Core\Misc\FPlatformUserId) UserId)> OnActivatedByProtocol;